Re: [PATCH] btrfs: fix lockdep warning with reclaim lock inversion

2014-04-14 Thread David Sterba
On Wed, Apr 09, 2014 at 05:23:23PM -0400, Jeff Mahoney wrote: 2 locks held by kswapd0/169: #0: (shrinker_rwsem){..}, at: [81159e8a] shrink_slab+0x3a/0x160 #1: (type-s_umount_key#27){..}, at: [811bac6f] grab_super_passive+0x3f/0x90 Signed-off-by: Jeff Mahoney

Re: [PATCH] btrfs: fix lockdep warning with reclaim lock inversion

2014-04-09 Thread Filipe David Manana
On Wed, Mar 26, 2014 at 6:11 PM, Jeff Mahoney je...@suse.com wrote: When encountering memory pressure, testers have run into the following lockdep warning. It was caused by __link_block_group calling kobject_add with the groups_sem held. kobject_add calls kvasprintf with GFP_KERNEL, which gets

Re: [PATCH] btrfs: fix lockdep warning with reclaim lock inversion

2014-04-09 Thread Jeff Mahoney
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 4/9/14, 12:05 PM, Filipe David Manana wrote: On Wed, Mar 26, 2014 at 6:11 PM, Jeff Mahoney je...@suse.com wrote: When encountering memory pressure, testers have run into the following lockdep warning. It was caused by __link_block_group

[PATCH] btrfs: fix lockdep warning with reclaim lock inversion

2014-04-09 Thread Jeff Mahoney
When encountering memory pressure, testers have run into the following lockdep warning. It was caused by __link_block_group calling kobject_add with the groups_sem held. kobject_add calls kvasprintf with GFP_KERNEL, which gets us into reclaim context. The kobject doesn't actually need to be added

[PATCH] btrfs: fix lockdep warning with reclaim lock inversion

2014-03-26 Thread Jeff Mahoney
When encountering memory pressure, testers have run into the following lockdep warning. It was caused by __link_block_group calling kobject_add with the groups_sem held. kobject_add calls kvasprintf with GFP_KERNEL, which gets us into reclaim context. The kobject doesn't actually need to be added

Re: [PATCH] btrfs: fix lockdep warning with reclaim lock inversion

2014-03-26 Thread David Sterba
On Wed, Mar 26, 2014 at 02:11:26PM -0400, Jeff Mahoney wrote: When encountering memory pressure, testers have run into the following lockdep warning. It was caused by __link_block_group calling kobject_add with the groups_sem held. kobject_add calls kvasprintf with GFP_KERNEL, which gets us